Internal combustion engine



Oct. 17, 1933. L. M. WOOLSON INTERNAL COMBUSTION ENGINE 2 Shoots-Sheet 1 Filed March 25, 1929 LJUNEL 1'1 NauLsaM.

Patented on. 17, 1933 UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE Lionel M. Woolson, Detroit, Mich., assignor to Packard Motor Car Company, Detroit, Mich, a corporation of Michigan Application March 25, 1929. Serial No. 349,685

3 Claim.

This invention relates to internal combustion engines and more particularly to fuel feeding Air enters the system through agitation caused by the pump or otherwise, leaky connections, draining of the supply tank and disconnection of parts. The trapped air travels with the oil, and even though it may collect in pockets in the line, it will eventually reach the fuel injection pumps where the main difiiculty is encountered. In order to prevent the entrance of air into the injector pumps, it is customary to provide air relief valves so that the system can be purged from time to time. While purging in this manner may have some effect in removing air from the system, considerable time must be consumedand only a portion of the trapped air is actually removed.

Air is elastic and when lodged in the injection devices it will be alternately compressed and then expanded because the oil is intermittently under high pressure, and as a result there will. be a prolonged steady flow of oil from the pumps after the pressure is relieved causingirregular running and the use of an excessive quantity of oil. Furthermore, starting the engine with air in the injection pump structures will considerably increase the time required to start combustion because many strokes of the injection pump are sometimes necessary before the air is forced out. a

It is an object of my invention to greatly reduce the above difficulties in fuel feeding systems for internal combustion engines of the self-igniting type by providing a manifold through which a quantity of fuel, several times in excess of the maximum injection quantity required by the associated injection devices, is constantly moved during operation of the engine.

Another object of my invention is to utilize the fuel, in a liquid fuel feeding system for internal combustion engines, to prevent air in the feed line of the .system from remaining stationary and collecting.

Another object of my invention is to provide a fuel feeding system in which the fuel travels in a circuit from which quantities are withdrawn as required for injection into the cylinders.

A further object of the invention is to provide a fuel feeding system for multi-cylinder engines in which the feed line extends in an upward direction substantially throughout the entire length so that there will be no re-entrant spaces or pockets in which air can accumulate.

Still another object of the invention resides in a'method for conducting liquid fuel to the injection devices of a self-igniting enginewherein a minimum quantity of air will reach the injection devices.

Other objects of the invention will appear from the following description taken in connection with the accompanying drawings which form a 5 part of this specification, and in which:

Fig. 1 is a rear elevation. of a radial engine with which my invention is associated;

Fig. 2 is a diagrammatic view of an engine and the fuel feeding system, and

Fig. 3 is a fragmentary view, partly in elevation and partly in section, of one section of the feeding system showing the connection of the manifold with one of the fuel injection devices.

Referring now to the drawings, 1 have illustratedmy invention associated preferably with a radial type of internal combustion engine in which explosions occur through compression in the cylinders. A central circular crank case 10 is formed with peripheral openings which are covered-by the cylinders 11 which are secured to the case and the usual crank shaft 12 extends centrally of the case and is connected to pistons (not shown) operating in the cylinders in a C0117 ventional manner. The engine. shown is of the 35 four cycle type and a single port 13 isprovided in the cylinder heads for air inlet and exhaust purposes, the port being controlled by a valve operating intermittently through mechanism contained in the housing 14 and actuated by a rod 90 within each housing 15 which is reciprocated by the crank shaft.

A fuel system is associated with the cylinders and the crank shaft for feeding oil directly into the cylinders in atomized form and in such manner that the presence of air in the fuel oil will notifiterfere with the proper functioning of the injection device. To this end I provide a low pressure pump for circulating the oil in a circuit with the-sourceof supply, and which includes a manifold arranged so that the travel of oil therethrough is continuously in an upward plane.

A pump chamber is formed by the housing 16 and the cover plate 17 secured to the end of the casing by means of bolts 18, bolts 19 securing this housing to the cover plate. A pair of meshing gears 20 and 21 are respectively supported within the housing by shafts 22 and 23, the shaft 23 projecting through the cover plate and carrying a gear 24 on its end. The gear 24 is rotated by a gear 25 on the crank shaft through an intermediate gear 26 which is suitably mounted on a shaft 27 within the crankcase. The pump casing is provided with an inlet extension 28 to which one end of a conduit 29 is secured by a suitable clamp 30, and an outlet extension 31 has one end of a conduit 32 secured thereto by a clamp 33. The conduit 29 extends to the bottom of a fuel oil supply tank 34 and is secured in open communication therewith. The tank has the usual filler cap 35 which is formed with an air vent 36 and closes the opening through the tank neck 37. The pump operates with the crank shaftand causes fuel oil in the conduit 29 leading from the bottom of the supply tank to move into the conduit 32 and then through the manifold.

A fuel injection device is associated with each cylinder and as such devices are similar I will describe only one. The casing 38 is arranged to receive a cylinder 39 in which a high pressure pump '40 is reciprocated intermittently from the crankshaft, the coil spring 41 serving to return the plunger to, non-compressing position after the injection stroke. The cylinder and casing are provided with a plurality of annularly arranged fuel inlet ports 42 through which fuel can pass from the manifold when uncovered by the plunger 40. A check valve 43 is arranged in the cylinder to prevent back flow of 'fuel 'which has been moved therebeyond, and associated with the upper end of the pump casing and cylinder is a nozzle 44 which extends transversely thereof and projects-through an opening in the cylinder wall. A nozzle suitablefor this purpose is shown in Patent 1,690,893 granted to Hermann Dorner, November 6, 1928. It will be seen that oil traveling through the manifold under low pressure will fiow into the nozzle through ports 42 when uncovered by the plunger 40 and will maintain the nozzle full of oil after each injection stroke of the pump. Oil passing into the cylinder from the nozzle is atomized by its passage through a small orifice and under a pressure of 2,000 pounds or more exerted by the pressure stroke of the plunger. V

The fuel feeding manifold is made up of a plurality ofhousing sections 50 and conduit sections 51 which extend between and connect the housing sections. The pump barrels are provided with spaced annular flanges 52, the peripheral edges of which are conical, and likewise the inlet housings are provided with inwardly extending flanges 53 which are arranged to be wedged into leak proof contact with the pump barrel flanges. The pump barrel is threaded to accommodate the nut 54 which is screwed up against the inlet housing to wedge and secure it in position. The housings are each provided with oppositely disposed extensions in the form of hollow screw plugs 55, the ends of which communicate with the ports 42 and a circular screen 56 is arranged between the flanges 53 of the housing so that the oil is filtered before passing into the pump. A T union 70 connects the lower end of the conduit 32 with conduit sections 51 extending to the two lowermost cylinders.

Connections are provided between the conduit sections 51 and the plug housing extensions, and to this end I provide an angular fitting 57 having a head portion 58 encircling the plug extension and an open end portion 59. There is a passage in the fitting which communicates with the plug through ports 60 enclosed by the, fitting head, and gaskets 61 are arranged between the fitting head and the outer flange end of the plug to the extension 65 by clamps 67 and is attached at the other end in communication with the top wall of the fuel supply tank.

The manifold, the pump and the connection between the pump and manifold are made of cross sectional area sufiicient to allow a quantity of oil to flow therethrough several times that required by the fuel pumps, and I have found that oil flowing through the manifold in a quantity six times the maximum total quantity required by the injection pumps gives very satisfactory results. The oil travels in a circuit which includes the tank, the pump and the manifold, the fuel injection devices receiving oil from the manifold as required and the excess oil travels from the manifold back to the supply tank. As the oil travels upwardly in all portions of the manifold, there are no re-entrant portions in which air can become pocketed. The quantity of oil traveling in circuit, being several times in excess of that required by the maximum injections of the pump devices, will insure that nearly all of any air in the fuel will be swept through the manifold and will flow into the supply tank so that the air which enters the injection devices is negligible. It will be understood that air in the quantity returning to the supply tank will escape through the vent in the filler cap.

It will be understood that various forms of the invention other than those described above may be used without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an internal combustion engine of the compression-ignition type, a plurality of radial cylinders, an individual engine operated fuel injection device fixed to each cylinder and arranged to discharge atomized liquid fuel into the associated cylinder, each of said devices including a feed passage and a pump plunger for closing the feed passage and discharging trapped fuel from the device under high pressure, a substantially circular manifold including housings fixed to the devices in open communication with'the feed passages therein and conduits connecting adjacent housings, said manifold extending in a vertical plane and having a capacity several times the requirements of the injection devices, a vented fuel reservoir, an inlet connection between the bottom of the manifold and the reservoir, an out-. let connection between the top of the manifold and the reservoir, and a pump associated with the inlet connection for moving fuel in a comtinuous stream through the manifold and into the feed passages of the injection devices when uncovered by the pump plungers.

2. In an internal combustion engine of the compression-ignition type, a plurality of radial cylinders, an individual engine operated fuel in jection device fixed to each cylinder and arranged to discharge atomized liquid fuel into the asso-- ciated cylinders, said devices each including a feed passage and a pump plunger for closing the feed passage and discharging the fuel trapped thereby from the device under high pressure, a fuel feeding manifold extending in a vertical plane including a, housing fixed to each injection device in open communication with the feed passages and detachable conduits connecting adjacent housings, and means for moving a stream of fuel in a circuit through the manifold under low pressure.

3. In an internal combustion engine of the compression-ignition type, a plurality of radial cylinders, an individual engine operated fuel injection device fixed to each cylinder and arranged to discharge atomized liquid fuel into the associated cylinder, said devices each including a feed passage and a pump plunger for closing the feed passage and discharging trapped fuel from the device under high pressure, a substantially circular manifold extending in a vertical plane including housings fixed to the devices in open communication with the feed passages and conduits connecting adjacent housings, said manifold having a capacity several times the requirements of the injection devices, a vented fuel reservoir, an inlet connection between the bottom of the manifold and the reservoir, an outlet connection associated in open communication with the uppermost housing and connected with the reservoir, and a pump associated with the inlet connection for moving fuel in a continuous stream through the manifold and into the feed passages of the injection devices when uncovered by the pump plungers, the excess fuel from the manifold returning to the reservoir through the outlet connection.

- LIONEL M. WOOLSON. 

